Here's a good article on Marincin from earlier this month: http://www.coppernblue.com/2015/6/12/8765883/martin-marincin
What we can confirm from his 85 games in the NHL is that he is a fantastic skater who can move the puck well and win one-on-one battles. Being 23, he's likely to make a mistake here and there, but he has shown signs of the defensive acumen needed to succeed at the NHL level. This past season was an interesting one for him, as he played very tough minutes at even strength for a weak Oilers team, yet still posted respectable possession numbers and shot share totals.
One number that stands out from the advanced metrics is the percentage of offensive zone starts, or lack thereof, Marincin had last season. Even though he started far more often in the defensive end against tougher competition compared to his teammates on defense, he still managed a respectable Corsi rating relative to his team.